Networked devices are now an extremely important aspect of our social fabric. The public switched telephone network (“PSTN”) is perhaps the first example of a ubiquitous network of telecommunication devices that changed the way people interact. Now, mobile telephone networks, the Internet, local area networks (“LAN”), wide area networks (“WAN”), voice over internet protocol (“VOIP”) networks, are widely deployed and growing.
It is trite to say that each of these devices need to be able to reach each other in order to fulfill networking functions. With the PSTN, a system of telephone numbers is employed, including country codes, area codes, local exchanges, etc. At least in North America, the explosion of telephonic devices has stretched the standard ten digit number scheme. With the Internet, the Internet Protocol Version 4 (“IPV4”) promulgates a system of Internet Protocol (“IP”) addresses to identify points on the Internet, and thus each networked device has an address making it reachable on the Internet. Due at least in part to the limited length of the IPV4 address field, IP addresses can bear little geographic relationship to their physical location. As a result, routers and routing tables throughout the Internet are extremely bloated, increasing complexity in traffic routing and increasing network latency. IPV6 offers potential relief addresses, but the upgrade to IPV6 is expected to be slow.
In very general terms, many prior art network architectures rely on routing devices to maintain addresses and locations of the devices throughout the network. Such routing devices are essentially traffic cops, routing traffic along appropriate pathways. Such architectures become clumsy and awkward as the networks grow.
Various “router-less” network architectures have been proposed. Some of these architectures are referred to as peer-to-peer networks, while others are referred to as ad-hoc networks. Regardless, these prior art architectures also tend to suffer from scaling and/or other limitations. One attempt to improve network architectures is Ad Hoc On Demand Distance Vector (“AODV”). AODV is a reactive protocol that uses a broadcast flood in order to establish a new connection or fix a broken connection. AODV is described in detail in the Internet Engineering Task Force (“IETF”) document found at http://www.ietf.org/rfc/rfc3561.txt. While AODV has the advantage of being able to easily organize nodes into an ad-hoc network one of the problems it has is that the maximum network size is extremely limited.
Another attempt to improve network architectures is ‘Destination Sequenced Distance Vector’ (“DSDV”). DSDV is a proactive protocol that uses a constant flood of updates to create and maintain routes to and from all nodes in the network. A detailed description of DSDV is found at http://citeseer.ist.psu.edu/cache/papers/cs/2258/http:zSzzSzwww.srvloc.orgzSzcharliepzSz txtzSzsigcomm94zSzpaper.pdf/perkins94highly.pdf or http://citeseer.ist.psu.edu/perkins94highly.html. While DSDV has the advantage of providing loop free routing it has the disadvantage of a only working in small networks. In large networks the control traffic easily exceeds the available bandwidth.
Another attempt to improve network architectures is ‘Optimized Link State Routing’ (“OLSR”). OLSR is a proactive protocol that attempts to build knowledge of the network topology. A detailed description of OLSR can be found in this IETF draft http://hipercom.inria.fr/olsr/draft-ietf-manet-olsr-11.txt. While OLSR has the advantage of being a more efficient link state protocol it is still unable to support larger networks.
Another attempt to improve network architectures is ‘Open Shortest Path First’ (“OSPF”). OSPF is a proactive link state protocol that is used by some internet core routers. A detailed description of OSPF can be found in this IETF draft http://www.ietf.org/rfc/rfc1247.txt. While OSPF allows core internet routers to route around failure is has limitations on the size of networks it is able to support.
Despite the differences between AODV, DSDV, OLSR and OSPF they all share some, of the same problems—e.g. the difficulty of scaling past a few hundred nodes. This limitation occurs because as the network grows, the amount of control traffic required grows much faster. Rapidly, the amount of control traffic needed will exceed the capacity of the network
In general, prior art network architectures do not provide the good scalability, nor do they provide the ability to allow low capacity devices to fully interact with the larger network, and in mobile environments, prior art architectures do not always provide seamless mobility.